Malicious apps can be inserted into the IPhone which was done by the researchers from Georgia Tech's Information Security Center (GTISC). They claim to have created an app “which rearranges its own code to create new functionality that is not exhibited during Apple’s approval process. This allows the malicious aspects of the app to remain undetected when reviewed and therefore obtain Apple’s approval.”

They further claim that it “can successfully perform many malicious tasks, such as posting tweets, taking photos, sending email and SMS, and even attacking other apps – all without the user’s knowledge.” They have published their finding and explain its research here.

They have further created a “malicious charger” called "Mactans". The “charger” is not a charger but a single-board computer concealed within the carapace of a charger and packing software that allows it to rummage about in iOS' innards and do nasty things to them.